To enhance the safety of a vehicle and passengers in present-day road traffic, in addition to providing extra-vehicular traffic guidance systems, efforts are being made to support the operator in routine driving operations as well as in extraordinary situations using systems that intervene automatically in the control of the vehicle or of particular vehicle components. Some systems involve GPS tracking with a central evaluation unit that can handle multiple vehicles simultaneously. More commonly, control safety devices are built into vehicles.
A first step in this direction was the adoption of antilock braking systems (ABS) and anti-slip regulation (ASR) to enhance longitudinal vehicle stability during braking and accelerating processes. Emergency triggering of such systems has been developed in response to a variety of sensor data. Sensor data may be data on the condition of the vehicle operator, the condition of the vehicle, or the condition of the environment around the vehicle.
In addition, use is made of so-called dynamic regulation (DR) and/or stability regulation (SR) to enhance transverse stability in dynamically critical situations, particularly in situations brought about and influenced by steering-wheel action taken by the operator. DR evaluates sensor data provided by suitable sensors from particular vehicle components or from the vehicle as a whole and correlates the data using special algorithms. In this way it is possible to recognize critical situations and, by taking positive action with respect to individual parameters of vehicle dynamics (for example steering-wheel angle and/or speed and acceleration), to influence the vehicle positively with reference to the transverse dynamically critically situation. Here especially the traction between the tires and the roadway also plays an important part, since the transmission of force between the vehicle and the roadway during vehicle control actions depends directly upon the traction.
However, DR acts according to pre-programmed parameters and limits with reference to the environment of the vehicle, comprising, for example, the road condition and other moving vehicles in the vicinity. Thus DR alone cannot be employed to evaluate the effectiveness of physically meaningful control actions affecting the motion of the vehicle. From the data reported concerning the environment and the vehicle's condition or motion parameters, the DR or SR evaluating unit continuously calculates target parameters for influencing the motion of the vehicle. These target parameters may be used to control the vehicle directly, but they are also analyzed to ascertain whether a conceivable collision may yet be prevented or is imminent. If a predetermined critical level of danger is not recognized by these analyses, the operator of the vehicle retains complete freedom to decide how to correct for dangers such as how to avoid an obstacle. Only when impending collision ascertained by the evaluating unit is no longer avoidable by any conceivable rational steering and/or braking control of the vehicle will an automatic emergency braking to produce rapid deceleration of the vehicle be triggered. Clearly there exist limits on the effectiveness of such a system given the difficulties of programming an evaluation unit with data adequate to the calculation of the vast array of conditions and responses possible. Inadequacy of such programming can lead to unnecessary loss of operator control of the vehicle if the evaluating unit takes over due to faulty parameter evaluation.
In these systems the type of sensors utilized can be selected from any number of commercially available sensors such as motion sensors, infrared sensors, position sensors, audio sensors, video sensors, chemical sensors, sound sensors, touch sensors or radio frequency sensors, or any combination thereof. The data from the sensors are processed according to pre-determined concepts of what the safety limits are for the components being monitored. When the limits are violated, response mechanisms are triggered and are known in general to include a variety of warning signals and ways to enable or to disable various components of the vehicle.
Gehlot in U.S. Pat. No. 6,060,989 describes in general such a system for preventing or reducing vehicle accidents comprising one or more sensors positioned on a vehicle sensing a condition or conditions indicative of a driver's ability to effectively control the vehicle and a processing unit in communication with the sensors. The processing unit receives data from the sensors, analyzes the data to determine an appropriate response and initiates the response. The plurality of sensors senses a condition such as steering column movement, driver head movement, driver eye movement, driver body movement, slurred speech, snoring, alcohol in breath, road conditions, proximity to road side edges, proximity to road paint strips or roadway obstacles. An audio signal may be initiated at the same time the corrective response is initiated by the processing unit to alert the operator and others in the vicinity. No details are provided as to what type of audio signal could be given. Further, no mention of sensors to detect tire conditions is included.
While Gehlot is primarily focused on operator ability to effectively control the vehicle, Mai, et al. in U.S. Pat. No. 6,084,508 describes a method and arrangement for emergency braking of a vehicle that includes a detection system on the vehicle which detects obstacles located in or near the direction of motion of the vehicle and generates corresponding data in an evaluating unit. Upon determining that an impending collision of the vehicle with an obstacle is no longer avoidable by any action on the vehicle by steering or braking, the system triggers an automatic emergency braking for rapid deceleration of the vehicle. The sensors may include sensors for detecting at least one of steering angle, vehicle speed and vehicle angle of yaw, or for determining the traction between roadway and the vehicle tires. Preferred sensors include at least one of a radar sensor and a laser sensor. No early warning signals are given and tire condition is not disclosed as measured by the sensors.
Vallancourt in U.S. Pat. No. 6,263,282 describes a dangerous driving condition warning system for a vehicle. The warning system captures signals from two or more devices in an automobile, such as speedometer, distance measuring device, and airbag, and conveys the signals to a decision circuit. The decision circuit determines whether a dangerous driving condition exists and outputs an activation signal upon detecting a dangerous condition. The activation signal is sent to and activates an indicator such as a warning light or loud audible warning. The warning indicator alerts a trailing vehicle and other vehicles near the vehicle equipped with the warning system of the existence of one of various conditions warranting caution, a reduction in speed, or a veering or turn. The decision circuit is capable of detecting one or more dangerous driving conditions in the group consisting of anti-lock brake activation, slippery road conditions from loss of adequate traction, tailgating, rapid deceleration, airbag deployment, and excessive approach speed by another automobile. The early warning system is intended as a cautionary signal for others in the vicinity and not discussed as a warning to alert the operator to the need for corrective action.
U.S. Pat. No. 5,481,243 to Lurie, describes a vehicle deceleration detection circuitry system, whereby the rear brake lights of an automotive vehicle may be controlled as a function of the deceleration of the vehicle. Lurie also contemplates an additional audible alert buzzer or horn that is activated to provide additional warning in the event of emergency braking. Again the audible warning is concurrent with the emergency deceleration/braking and not intended as an early alert to the driver as to the need for corrective action.
Lisiak, et al. in U.S. Pat. No. 6,271,746 describes methods and devices for controlling the use of an automotive horn as a function of the speed, motion, vibration or acceleration of the automotive vehicle. The invention contemplates methods and devices for disabling the automotive horn for a certain period of time, abating the volume or noise level of the horn, or modifying the tone or sound of the horn to a tone or sound considered less offensive. In certain embodiments, the method of control includes electronic methods for controlling the horn by connection to the speedometer, accelerometer or braking system of the vehicle. Alternatively, motion sensors, vibration sensors, or acceleration sensors may be used to control the horn. For example, the invention contemplates a device that will disable the horn upon the attainment of a predetermined reading or value on one or more of the sensors for speed, brake activation, motion, vibration, acceleration or deceleration. The use of the horn in this scenario is considered to be excessive and needing to be curbed by various disabling or muting mechanisms. The operator can not force a return to normal horn functioning except after a predefined lock-out control period of time.
Automotive horns are installed in almost all automobiles, trucks and other automotive vehicles. Automotive horns are intended for use as a warning device to provide warning to other drivers, bicyclists, pedestrians, bystanders, or animals of potentially dangerous conditions in the vicinity of the automobile. For example, the horn may be used to warn pedestrians or persons in the path or vicinity of a moving vehicle of the presence or location of the vehicle. However automotive horns are not commonly described as alert warning devices for vehicle operators. The present invention overcomes this oversight.
The prior art systems and reliance on police presence are inadequate to meet the demands of eliminating or reducing drunk drivers and those who are too tired or ill to be driving effectively. Further, there is a need for better early detection of and alerting of the operator to unsafe driving conditions to allow effective operator intervention as well as for rapid emergency braking should operator intervention be ineffective.